| Document and Entity Information | Jan. 28, 2021 |
| Document And Entity Information [Line Items] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jan. 28, 2021 |
| Entity Registrant Name | STIFEL FINANCIAL CORP. |
| Entity Central Index Key | 0000720672 |
| Entity Emerging Growth Company | false |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-09305 |
| Entity Tax Identification Number | 43-1273600 |
| Entity Address, Address Line One | 501 N. Broadway |
| Entity Address, City or Town | St. Louis |
| Entity Address, State or Province | MO |
| Entity Address, Postal Zip Code | 63102-2188 |
| City Area Code | 314 |
| Local Phone Number | 342-2000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Common Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Title of 12(b) Security | Common Stock, $0.15 par value per share |
| Trading Symbol | SF |
| Security Exchange Name | NYSE |
| Depository Shares, each representing 1/1,000th interest in a share of 6.25% Non-Cumulative Preferred Stock, Series A [Member] | |
| Document And Entity Information [Line Items] | |
| Title of 12(b) Security | Depository Shares, each representing 1/1,000th interest in a share of 6.25% Non-Cumulative Preferred Stock, Series A |
| Trading Symbol | SF-PA |
| Security Exchange Name | NYSE |
| Depository Shares, each representing 1/1,000th interest in a share of 6.25% Non-Cumulative Preferred Stock, Series B [Member] | |
| Document And Entity Information [Line Items] | |
| Title of 12(b) Security | Depository Shares, each representing 1/1,000th interest in a share of 6.25% Non-Cumulative Preferred Stock, Series B |
| Trading Symbol | SF-PB |
| Security Exchange Name | NYSE |
| Depository Shares, each representing 1/1,000th interest in a share of 6.125% Non-Cumulative Preferred Stock, Series C [Member] | |
| Document And Entity Information [Line Items] | |
| Title of 12(b) Security | Depository Shares, each representing 1/1,000th interest in a share of 6.125% Non-Cumulative Preferred Stock, Series C |
| Trading Symbol | SF-PC |
| Security Exchange Name | NYSE |
| 5.20% Senior Notes due 2047 [Member] | |
| Document And Entity Information [Line Items] | |
| Title of 12(b) Security | 5.20% Senior Notes due 2047 |
| Trading Symbol | SFB |
| Security Exchange Name | NYSE |
